Tommy John surgery saves baseball careers by replacing a torn elbow ligament with a healthy tendon from elsewhere in the body.

Tommy John surgery, medically known as Ulnar Collateral Ligament (UCL) reconstruction, was first performed on September 25, 1974, by Dr. Frank Jobe. At the time, Dr. Jobe estimated the pitcher's chances of returning to the mound at only 1 in 100. Tommy John defied these odds by pitching 14 more seasons and winning 164 additional games after the operation.The UCL is a thick band of tissue on the inner side of the elbow that keeps the joint stable during the high-velocity overhead throwing motion. During a pitch, the elbow can experience torque equivalent to hitting the arm with a hammer, which frequently leads to microscopic tears or a complete rupture of the ligament. To fix this, surgeons typically harvest the palmaris longus tendon from the patient's own forearm or a hamstring tendon from the leg.The surgeon drills holes in the humerus and ulna bones and threads the harvested tendon through them in a figure-eight pattern to create a new, functional ligament. While the surgery itself takes about 90 minutes, the rehabilitation process is grueling and usually lasts 12 to 18 months. Modern advancements have significantly improved success rates, with studies from the American Journal of Sports Medicine showing that 80% to 90% of professional pitchers now return to their previous level of play.